The subject invention is directed toward the art of welding and, more particularly, to an orbital welding apparatus for circular products such as tubes or rods.
The invention is especially suited for incorporation in apparatus for welding small diameter tubing in closely confined spaces and will be described with references thereto. It should be appreciated, however, that the invention is capable of broader application and could be used in many different welding devices of widely varying sizes for many purposes.
Orbital arc welding equipment is often used to weld tubing and piping for use in fluid handling and processing system. Currently, there is significant interest in welding small diameter tubing, fittings, and control equipment such as valves, filters, and the like to form small, compact control and processing systems. Frequently, the various components must be welded in confined and nearly inaccessible areas. In addition, system designers are desirous of reducing, to the greatest extent possible, the size of the processing and control systems by reducing the distance between components. Much effort has been expended in miniaturizing tube fittings and system components; however, the space required by the welding apparatus has been a significant limitation on further system size reduction.
Safe use of potentially dangerous equipment has long been a concern in all areas of manufacturing and repair services. Fail-safe electrical interlocks are one of the various methods of ensuring operator safety during use of such equipment. Generally, electrical interlocks have met with great success and are therefore widely accepted in all areas of manufacturing and repair services.
The subject invention provides a unique combination of features which allows welds to be made safely in extremely confined spaces and under conditions which have heretofore prevented use of orbital welding equipment. The invention makes it possible to obtain the maximum system size reduction benefits through the use of miniaturized fittings and components.